Levetiracetam-induced cutaneous adverse drug reactions were not associated with HLA genes in a small sample of Chinese patients with epilepsy

Identification of significant immune-related genes for epilepsy via bioinformatics analysis

Background

Epilepsy is one of the most common neurological disorders, but its underlying mechanism has remained obscure, and the role of immune-related genes (IRGs) in epilepsy have not yet been investigated. Therefore, in this study, we explored the association between IRGs and epilepsy.

Methods

An IRG list was collected from the ImmPort database. The gene expression profiles of GSE143272 were collected from the Gene Expression Omnibus (GEO) database (https://www.ncbi.nlm.nih.gov/geo/). Differentially expressed genes (DEGs) between epilepsy and normal samples were analyzed, and the intersections between IRGs and DEGs were identified using the VennDiagram package, with the intersected genes subjected to further analysis. Enrichment function for intersected genes were performed, constructed a protein-protein interaction (PPI) network via the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database, and the hub genes (top 10) of the PPI network were calculated by the cytoHubba plug-in in Cytoscape. The top correlated genes were selected to perform correlation analysis with immune cells infiltration and expression levels. Finally, we performed validation of the top correlated genes transcriptional expression levels using an animal model.

Results

There were a total of 245 DEGs detected in GSE143272, among which 143 were upregulated and 102 downregulated genes in epilepsy. A total of 44 differential IRGs were obtained via intersection of DEGs and IRGs. Enrichment function analysis of DEGs showed that they played a significant role in immune response. The gene CXCL1 was the most correlated with other differentially expressed IRGs via the PPI network. The results of immune cell infiltration analysis indicated that epilepsy patients had higher activated mast cells infiltration (P=0.021), but lower activated CD4 memory T cells (P=0.001), resting CD4 memory T cells (P=0.011), and gamma delta T cells (P=0.038) infiltration. It was revealed that CXCL1 and activated mast cells (R=0.25, P=0.019) and neutrophils (R=0.3, P=0.0043), and a negative correlation with T cells gamma delta (R=−0.25, P=0.018). The levels of CXCL1 expression were significantly lower in epilepsy patients than those in normal samples.

Conclusions

In this study, the results showed that IRGs such as CXCL1 have a significant influence on epilepsy via regulation of immune cells infiltration.

Spectrum of Cutaneous Adverse Reactions to Levetiracetam and Human Leukocyte Antigen Typing in North-Indian Patients

Background and Purpose

Aromatic antiepileptic drugs are frequently implicated for cutaneous adverse drug reactions (cADRs); there are case-reports of even severe reactions like drug reaction eosinophilia and systemic symptoms (DRESS) and Stevens Johnson syndrome (SJS)-toxic epidermal necrolysis with Levetiracetam (LEV). Certain human leukocyte antigen (HLA)-alleles have strong association with cADRs due to specific drugs - HLA-B*15:02 and HLA-A*31:01 in Carbamazepine (CBZ)-related SJS in Han-Chinese and European populations, respectively. Here, the spectrum of cADRs to LEV was studied, and HLA-typing in patients with cADRs due to LEV and some who were LEV-tolerant was performed, in an attempt to find an association between HLA and such reactions.

Methods

589 patients taking LEV were screened for skin reactions, and eight patients with LEV-related cADRs and 25 LEV-tolerant controls were recruited - all 33 of North Indian ethnicity, their HLA-A, B, DRB1 genotyping done. Statistical analysis was done to compare carrier-rates and allele-frequencies of HLA-alleles between cases and controls (and healthy population, where necessary) for alleles occurring more than two times in either group.

Results

Out of 589 patients on LEV screened, there were 8 cases of cADR: 5 with maculopapular exanthema (MPE), 2 of SJS, and 1 with DRESS. Although HLA-A*33:01 was seen to occur more in MPE cases as compared to tolerant controls, the difference was not statistically significant (odds ratio [OR] 6.00, 95% confidence interval [CI] 0.30–116.6; p = 0.31). HLA A*11:01 and 24:02 were found to occur more in LEV-tolerant controls than in cases (OR 0.23 [95% CI 0.02–2.36, p = 0.33] and 1.00 [95% CI 0.09–11.02, p = 1.00] respectively).

Conclusions

Cutaneous reactions to LEV are very unusual, and their association with HLA in North-Indian population was not statistically significant.